1. Technical Field
This invention relates to the high-performance end-to-end delivery of online multimedia services, including Internet services such as World Wide Web (WWW) access. The invention combines a scalable, hierarchical, distributed network architecture and processes for replicating, caching, and multicasting.
2. Description of Related Art
Cable modems enable an end-user to make a high-bandwidth connection to a network system. For example, using a digital modulation technique called quadrature phase-shift keying (QPSK), a downstream connection with a bandwidth of about 10 megabits per second may be made by occupying a single 6 MHz channel out of the 750 MHz total coaxial capacity typical in most modern cable television systems, and an upstream connection with 768 kilobits per second may be made by occupying 600 KHz of that capacity. The bandwidth may be increased or decreased by occupying more or less bandwidth as desired. Other modulation techniques are also available, such as quadrature-carrier amplitude modulation (QAM). The technology for such connections is available, for example, from companies such as Motorola, the LanCity division of Bay Networks, and Hewlett Packard. Unlike telecommunications connections that use dedicated switched lines, cable modem connections use a shared medium and so can be continuously xe2x80x9conxe2x80x9d without substantial waste of resources.
Although cable modems provide a practical high-speed connection from the end-user to the network, nevertheless, such a high-speed connection is not enough by itself to deliver high-performance online services, especially with regards to Internet services, such as World Wide Web (WWW) access. In order to deliver high-performance end-to-end Internet service, solutions are needed to the problems of redundant data traffic, unreliable network performance, and scalability.
The Internet is a publicly accessible internetwork of networks. Internet Service Providers (ISPs) provide Internet access to businesses and consumers via points of presence (POPs) that are connected to network access points (NAPs) which are entry points to the Internet.
One of the Internet""s architectural weaknesses, and the cause of many of its current performance issues, is its highly redundant data traffic. For example, when an end-user downloads a video clip from the popular CNN (Cable News Network) Web site, data packets containing bits of the video clip are xe2x80x9cpulledxe2x80x9d all the way across the Internet: from the CNN WWW server, to CNN""s ISP (ISP), through potentially several paths across the Internet including multiple interchanges on the Internet backbone, to the end-user""s ISP, and finally to the end-user""s computer system. If the end-user""s next-door neighbor soon thereafter requests the very same video clip from the CNN Web site, she also pulls the bits of the clip all the way across the Internet. The result is that many of the same bits are moved over and over again over the same communication paths going to CNN""s ISP, across the Internet, and to the end-user""s ISP.
Another weakness of the Internet is its unreliable performance. The Internet performs in an intermittent or otherwise unreliable manner due in part to traffic bottlenecks which constrict the flow of data in the system. Unfortunately, there is no coherent scheme to deal with such bottlenecks because of the decentralized nature of the management of the Internet.
Yet another weakness of the Internet is its lack of security. This lack of security is particularly significant because it tends to inhibit electronic transactions and is in part due to the public nature of the Internet.
In order to provide for future growth for a network, it is important that the network architecture and operation be scalable to larger size and/or higher speeds. If the architecture is not readily scalable to a larger size, network performance will suffer when the network is expanded. If the network is not readily scalable to higher speeds, performance will suffer when network traffic increases.
The present invention relates to a system and method for delivering high-performance online multimedia services, including Internet services such as WWW access, that satisfies the above-described needs. The system and method combine a scalable, hierarchical, distributed network architecture and processes for replicating and caching frequently-accessed multimedia content within the network, and multicasting content customized per region or locality.
The digital network architecture couples a high-speed backbone to multiple network access points (NAPs) of the Internet, to a network operation center, to a back office system, and to multiple regional data centers. Each regional data center couples to several modified head-ends, which in turn couple via fiber optics to many neighborhood optoelectronic nodes. Finally, each node couples via coaxial cable and cable modems to multiple end-user systems. The architecture separates the public Internet from a private network with enhanced security to facilitate electronic transactions.
The backbone provides a transport mechanism that can be readily scaled to higher speeds. The backbone also enables bandwidth to the Internet to be increased, without reconfiguring the network structure, either by increasing the speed of the existing couplings at the NAPs or by adding a new coupling to a NAP. Finally, the backbone allows service to be extended to a new area, again without reconfiguring the network structure, by simply coupling a new regional data center (RDC) to the backbone.
The network operation center (NOC) is a centralized control center which efficiently coordinates the management of the privately controlled network. The network management system (NMS) server at the NOC coordinates NMS clients at the RDCCs. The management of the private network enables the optimization of performance. The hierarchical nature of the management allows consistent system configuration and management which results in a high level of overall network security and reliability.
Certain frequently-accessed information or content is cached within and replicated amongst the RDCs. This reduces traffic redundancy since an end-user""s request for data that has been so replicated or cached may be fulfilled by the xe2x80x9cnearestxe2x80x9d (most closely coupled) RDC. In addition, the RDCs are able to multicast content that has been customized for the region to end-users in the region. This further reduces redundant traffic. Finally, the RDCs contain NMS clients that monitor and proactively manage network performance in the region so that traffic bottlenecks may be identified and overcome. The NMS detects and figures out the locations of the faults throughout the network, correlates failures, and can report faults to the appropriate repair entities, create trouble tickets, and dispatch repair crews.
Frequently-accessed content is also cached within the modified head-ends. This further reduces redundant traffic because an end-user""s request for content that has been so cached may be fulfilled by the xe2x80x9cnearestxe2x80x9d modified head-end.
Finally, the hierarchical nature of the private network architecture enables multicast data to be efficiently customized for each region receiving the multicast.